Honestly, since you don't know anyone, it's going to be just a crapshoot no matter what you decide. CO people are usually pretty chill (albeit with the random assholes who mess up the averages). But overall no matter what pass you decide on, you should be able to find some people to ride with.

The bigger question is going to be things like your budget, your time, and the like. Some mountains are closer, some are further away. Do you want to drive less, and don't care if it's a "big" mountain? Go to Loveland or Eldora. Do you want the whole big mountain experience with lodges and restaurants and apres ski? Then do the mountains on the Epic Pass. Are you on a budget? The bigger mountains are going to cost more each trip for parking, food, lodging, etc. even if their pass price is pretty reasonable.

Another option is to do 4-packs. Several mountains offer 4-packs of tickets that you can use all season. You can buy sets from different places to get a feel for what each mountain has to offer.

You can't really go wrong. You are in one of the best spots in the world for skiing/riding. Welcome to paradise.